• Title/Summary/Keyword: $\delta^{13}C$

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Organic Matter Cycle by Biogeochemical Indicator in Tidal Mud Flat, West Coast of Korea (생지화학적 지표를 이용한 서해안 갯벌 퇴적층에서의 유기물 순환에 관한 연구)

  • Lee, Dong-Hun;Lee, Jun-Ho;Jeong, Kap-Sik;Woo, Han Jun;Kang, Jeongwon;Shin, Kyung-Hoon;Ha, Sun-Yong
    • Ocean and Polar Research
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    • v.36 no.1
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    • pp.25-37
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    • 2014
  • To understand the degradation processes of organic matter related to sulfate reduction by Sulfate Reduction Bacteria (SRB) in the tidal flat sediments of Hwang-do and Sogeun-ri, Tae-an Peninsula in Chungnam-do, biogeochemical characteristics were analyzed and highlighted using specific microbial biomarkers. The organic geochemical parameters (TOC, ${\delta}^{13}C_{org}$, C/N ratio, long-chain-n-alkane) indicate that most of the organic matter has been derived from marine phytoplankton and bacteria in the fine-grained sediment of Sogeun-ri, although terrestrial plant components have occasionally been incorporated to a significant degree in the coarse-grained sediment of Hwang-do. The concentration of sulfate in pore water is a constant tendency with regard to depth profile, while methane concentration appears to be slightly different with regard to depth profile at the two sites. Especially, the sum of bacteria fatty acid (a-C15:0 + i-C15:0 + C16:1w5) confirms that the these concentrations in Sogeun-ri are related to the degradation of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) compounds from the crude oil retained in the sediments as a result of the Hebei Spirit oil-spill accident in 2007. The methane-related microbial communities as shown by lipid biomarkers (crocetane, PMI) are larger in some sedimentary sections of Hwang-do than in the Sogeunri tidal flat. These findings suggest that methane production by microbiological processes is clearly governed by SRB activity along the vertical succession in organic-enriched tidal flats.

Optical Properties of Infinite-Layer Superconductors $Sr_{0.9}$$Ln_{0.1}$Cu$O_2$ (LnLa, Gd, Sm) (무한층 초전도체 $Sr_{0.9}Ln_{0.1}CuO_2$(Ln=La, Gd, Sm)의 광학적 성질)

  • Mun, Mi-Ock;Park, Young-Sub;Kim, Kibum;Kim, Jae H.;A. B. Kuzmenko
    • Progress in Superconductivity
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    • v.3 no.1
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    • pp.13-16
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    • 2001
  • We have measured the reflectivity of superconducting infinite-layer compounds $Sr_{0.9}$ $Ln_{0.1}$ Cu $O_2$ (Ln=La, Gd, Sm) with $T_{c}$ : 39 K using a Fourier-transform infrared spectrometer. We have identified the optical phonon modes from their infrared reflectivity and conductivity spectra and have proposed possible displacement patterns. The La- and the Gd-doped compounds exhibited only four ($2A_{2u}$ $+2E_{u}$) out of the five ($2A_{2u}$ $3E_{u}$) infrared-active phonons predicted by a group theoretical analysis whereas the Sm-doped compound exhibited all five modes. For the La-doped sample, we investigated the temperature dependence of the optical response functions in a wide temperature range of 7 - 300 K. In FIR region, the reflectivity is apparently enhanced below ~120 $cm^{-1}$ as temperature decreases across $T_{c}$. The value of $2$\Delta$/k_{B}$ $T_{c}$ is about 4.5, which is consistent with maximum gap value of d-wave $high- T_{c}$ cuprates.> c/ cuprates.uprates.s.

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Quality Characteristics of Clarified Apple Juices Produced by Various Methods (청징 사과주스의 제조 및 품질특성 비교)

  • Sohn Kyoung-Suck;Seog Eun-Ju;Lee Jun-Ho
    • Food Science and Preservation
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    • v.13 no.2
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    • pp.138-143
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    • 2006
  • Clarified apple juice was prepared using different clarification methods including centrifugation, ultrafiltration (UF), and combined treatment (CT). Effects of clarification methods as well as other qualify parameters were investigated Clarification was clearly improved with an increase in centrifugation speed and towering temperature. Especially, lowering the temperature led to a decrease in turbidity values at 5,000 rpm. The optimum condition for centrifugation process was $5^{\circ}C$ and 10,000 rpm, respectively. UF and CT were very effective to produce clarified apple juice. The optimum condition of UF process was $45^{\circ}C$ and 150 kPa considering flux and turbidity. L*-values were increased while a*-values were decreased significantly after clarification regardless of methods (P<0.05). Vitamin C was most retained in the clarified samples using CT.

Effect of Oil Addition on Texture of Mungbean Starch Gel (지방첨가가 녹두전분 Gel의 Texture에 미치는 영향 -제1보 : 이화학적 특성 및 기계적 검사에 의한 평가)

  • 주나미;전희정
    • Korean journal of food and cookery science
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    • v.7 no.4
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    • pp.63-69
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    • 1991
  • This study was undertaken for the purpose of studying the physicochemical propery of mungbean and texture of mungbean starch gels. Mungbean starch gel made with different levels of oil were tested to investigate the textural characteristics by mechanical test. The results are summerized as fallows: The content of moisture fat, protein, and ash in Seonwha mungbean were shown to be about 13.19%, 1.02%, 23.57% 3.13% respectively. Those of Seonwha mungbean crude starch were 12.48%, 0.63%, 0.94%, 0.13% respectively. The gain of dry crude starch from peeled mungbean was 22.48%. Water binding capacity of Seonwha mungbean crude starch was 183.1%. The pattern of change in swelling power of Seonwha mungbean crude starch for increasing temperature increased slowly to $70^{\circ}C$, and then increased rapidly. The pattern of change in solubility was similar to that of swelling power. The amylose and amylopectin content were 22.5%, 77.5%. Brabender hot-paste viscosities of mungbean crude starch at 8% and 10% showed the similar amylogram patterns with peak vicosity. By the Rheometer measurement result of 8% 10% mungbean starch gel, Hardness and Fractuability tended to be decreased as the addition level of oil increased. Elasticity, Adhesiveness, Chewiness, L, a, and b value tended to be increased as the addition level of oil increased.

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Classification by Zooplankton Inhabit Character and Freshwater Microbial Food Web: Importance of Epiphytic Zooplankton as Energy Source for High-Level Predator (동물플랑크톤의 서식 특성에 따른 분류와 먹이망: 상위포식자의 에너지원으로서 부착성 동물플랑크톤의 중요성)

  • Choi, Jong-Yun;La, Geung-Hwan;Jeong, Kwang-Seuk;Kim, Seong-Ki;Chang, Kwang-Hyeon;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
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    • v.45 no.4
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    • pp.444-452
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    • 2012
  • We conducted a comprehensive monitoring for freshwater food web in a wetland system (Jangcheok Lake), from May to October, 2011. Monthly sampling for zooplankton, fish as well as organic matters, was implemented. In order to understand the food web structure and energy flow, we applied stable isotope analysis to the collected samples, based on ${\delta}^{13}C$ and ${\delta}^{15}N$ values of epiphytic particulate organic matter(EPOM) and particulate organic matter (POM), epiphytic and planktonic zooplankton, fish (Lepomis macrochirus). In the study site, epiphytic and planktonic zooplankton was 24 and 30 species, respectively, and coincidence species between epiphytic and planktonic zooplankton were 20 species. Epiphytic zooplankton were more abundant during the spring and early summer (May to July); however, planktonic zooplankton were more abundant during the autumn (September to October) season. Stable isotope analysis revealed that fish and epiphytic zooplankton had seasonal variations on their food sources. EPOM largely contributed epiphytic zooplankton in spring (May), but increasing contribution of POM in autumn (September) was detected. However, planktonic zooplankton depended on only POM in both seasons. Fish utilized both epiphytic and planktonic zooplankton, but small sized (1~3 cm), fish preferred epiphytic zooplankton, where as larger sized (4~7 cm) fish tended to consume planktonic zooplankton, and epiphytic zooplankton had important role in energy transfer. This pattern was clear when results of spring and autumn stable isotope analysis were compared. From the results of this study, we confirmed that wetlands ecosystem supported various epiphytic and planktonic zooplankton species, they depend on other food items, respectively. L. macrochirus also showed a difference of food source according to the body size, they depend on seasonal density change of zooplankton. In particular, epiphytic zooplankton was very important for growth and development of young fish in the spring.

Physicochemical Properties of Starch in Water Chestnut (Eleocharis kuroguwai Ohwi) (올방개 괴경 전분의 이화학적 특성)

  • Kim, Sang-Kuk;Shin, Jong-Hee;Kim, Su-Yong;Kim, Hak-Yoon;Park, Shin-Young
    • Korean Journal of Weed Science
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    • v.32 no.3
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    • pp.204-210
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    • 2012
  • The physicochemical properties of tuber starch in water chestnut have been studied. Peak viscosity, hot paste viscosity and cooling peak viscosity were 5679, 3146 and 4262 RVU, respectively. In three transition parameters, onset temperature ($T_o$), peak temperature ($T_p$), and conclusion temperature ($T_c$) were 64.1, 68.5 and $72.3^{\circ}C$, respectively. Gelatinization enthalpy (${\Delta}H$ gel) was 4.48 J/g. A-type starch has a smaller proportion (11.4%) of short chains ($DP{\geq}12$) and a larger proportion (57.2%) of short chains ($13{\leq}DP{\geq}24$). The tuber starch of water chestnut displayed an A-type X-ray diffraction pattern showing a strong diffraction peak at $2{\Theta}$ values of $15.18^{\circ}$, $17.13^{\circ}$, and $23.1^{\circ}$, and a weak peak at $2{\Theta}$ values of $18.1^{\circ}$, $20.06^{\circ}$, and $26.69^{\circ}$. Their crystallinity was 28.6% and the mean starch granule size was 21.5 ${\mu}m$.

Skarn Formation in Metamorphic Rocks of the Chungju Mine Area (충주광산 지역 계명산층의 텅스텐 스카른화작용)

  • Kim, Gun-Soo;Park, Maeng-Eon
    • Economic and Environmental Geology
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    • v.28 no.3
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    • pp.185-197
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    • 1995
  • Tungsten skarns in the Chungju mine which consists mainly of strata-bound type iron ore deposits are found in the vicinity of the contact between the age-unknown Kyemeongsan Formation and granitic rock intrusions of Mesozoic age($134{\pm}2Ma$). Tungsten skarns were formed extensively from alumina and silica-rich schistose rocks by the introduction of calcium and iron from hydrothermal solution. The skarns comprise a metasomatic column and are subdivided into four facies; garnet facies, wollastonite facies, epidote facies and chlorite facies. The skarn process in time-evolutional trend can be divided broadly into the four facies in terms of the paragenetic sequence of calc-silicates and their chemical composition. Skarn and ore minerals were formed in the following sequence; (1) garnet facies, adjacent to biotite granite, containing mainly garnet(>Ad96) and magnetite, (2) wollastonite facies containing mainly wollastonite and garnet(Ad95~60), (3) epidote facies, containing mainly epidote(Ps35~31), quartz, andradite-grossular(Ad63~50), and scheelite, (4) chlorite facies, adjacent to and replacing schist, containing mainly chrolite, muscovite, quartz, calcite, epidote(Ps31~25), hematite and sulfides. The mineral assemblage and mineral compositions. suggest that the chemical potentials of Ca and Fe increased toward the granitic rock, and the component Al, Mg, K, and Si decreased from the host rock to granitic rock. The homogenization temperature and salinity of fluid inclusion in scheelite, quartz and epidote of epidote facies skarn is $300-400^{\circ}C$ and 3-8wt.% eqiv. NaCl, respectively. ${\delta}^{34}S$ values of pyrite and galena associated with chlorite facies skarn is $9.13{\sim}9.51%_{\circ}$ and $5.85{\sim}5.96%_{\circ}$, respectively. The temperature obtained from isotopic com· position of coexisting pyrite-galena is $283{\pm}20^{\circ}C$. Mineral assemblages and fluid inclusion data indicate that skarn formed at low $X_{CO_2}$, approximately 0.01. Temperature of the skarn mineralization are estimated to be in the range of $400^{\circ}C$ to $260^{\circ}C$ and pressure to be 0.5 kbar. The oxygen fugacity($fo_2$) of the skarn mineralization decreased with time. The early skarn facies would have formed at log $fo_2$ values of about -25 to -27, and late skarn facies would have formed at log $fo_2$ values of -28 to -30. The estimated physicochemical condition during skarn formation suggests that the principal causes of scheelite mineralization are reduction of the ore·forming fluid and a decrease in temperature.

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The Activity of Hypertension-related Protein Kinase C and the Relationship of Physical Therapy (고혈압-연관 단백질 부활효소 C의 활성과 물리치료의 상관성)

  • Kim, Jung-Hwan
    • The Journal of Korean Physical Therapy
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    • v.20 no.3
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    • pp.61-68
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    • 2008
  • Purpose: Protein kinase C (PKC) is a member of a family of serine/threonine kinases that are activated by diacylglycerol (DG) and PKC stimulants. PKC play a key role in signal transduction, including muscle contraction, cell migration, apoptosis, cell proliferation and differentiation. However, the mechanism relating mitogen-activated protein kinases (MAPKs) and PKC, especially in the volume-dependent hypertensive state, remains unclear. Methods: In the present study, I investigated the relationship between PKC and MAPKs for isometric contraction, PKC translocation, and enzymatic activity from normotensive sham-operated rats (NSR) and aldosterone-analogue deoxycorticosterone acetate (DOCA) hypertensive rats (ADHR). Results: Systolic blood pressure was significantly increased in ADHR than in NSR. Physiological salt solution (PSS)-induced resting tension and the intracellular $Ca^{2+}$ concentration ([$Ca^{2+}{_i}$]) were different in the ADHR and NSR. The expression of PKC$\alpha$, PKC$\beta$II, PKC$\delta$, PKC$\varepsilon$ and PKC$\xi$ were different between the cytoplasmic and membranous fractions. However, expression of the PKC isoforms did not differ for the ADHR and NSR. The use of 12-deoxyphorbol 13-isobutyrate (DPB, a PKC stimulant) induced isometric contraction in $Ca^{2+}$-free medium, which was diminished in muscle strips from ADHR as compared to NSR. Increased vasoconstriction and phosphorylation induced by the use of 1 ${\mu}$M DPB were inhibited by treatment with 10 ${\mu}$M PD098059 and 10 ${\mu}$M SB203580, inhibitors of extracellular-regulated protein kinase 1/2 (ERK1/2) and p38 MAPK from ADHR, respectively. Conclusion: These results suggest that the development of aldosterone analogue-induced hypertension is associated with an altered blood pressure, resting tension, [$Ca^{2+}{_i}$], and that the $Ca^{2+}$-independent contraction evoked by PKC stimulants is due to the activation of ERK1/2 and p38 MAPK in volume-dependent hypertension. Therefore, it is suggested that PKC activity affects volume-dependent hypertension and the need to develop cardiovascular disease-specialized physical therapy.

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Analysis of a.c. Characteristics in Cr-doped ZnO Using Dielectric Functions (Cr을 첨가한 ZnO의 유전함수를 이용한 a.c. 특성 분석)

  • Hong, Youn-Woo;Shin, Hyo-Soon;Yeo, Dong-Hun;Kim, Jong-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.16-16
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    • 2009
  • ZnO($Zn_{1+x}O$)는 n-type 반도성 세라믹스로 우수한 전기적, 광학적, 화학적 특성을 갖고 있어 바리스터, 투명 전도막, 화학 및 바이오 센서, UV light emitter 등 다양한 용도로 사용되고 있다. 또한 ZnO에 각종 천이 금속 산화물을 일정량 첨가함에 따라 발생하는 결함준위와 입계 특성의 변화에 대한 연구가 활발히 진행되고 있다. 다양한 천이 금속 산화물의 첨가에 따른 전기적 광학적 특성의 변화에 대한 결과들이 많이 보고되고 있지만 서로 상충되거나 해석상 다소 어려운 것으로 알려져 있다. 따라서 본 연구에서는 ZnO에 $Cr_2O_3$를 2.0 at% 첨가하여 Cr 첨가에 따른 ZnO의 결함준위와 입계 특성 변화에 대하여 각종 유전함수($Z^*$, $Y^*$, $M^*$, $\varepsilon^*$, and $tan{\delta}$)를 이용하여 고찰하였다 ZnO에 Cr을 첨가할 경우 결함 중 장범위 쿨롱 인력에 의한 결함(0.13~0.18 eV)이 ~100K 영역에서 나타났으며, ZnO 내 결함 중 대표적인 $Zn_j$$V_o$는 서로 겹쳐서 나타났다. 이들 중첩된 결함에 대하여 각종 유전함수를 이용할 경우 서로 분리해 낼 수 있는 강점이 있음을 논하였다. 또한 각 결함준위가 강는 정전용랑(C)과 저항(R)을 impedance-modulus spectroscopy를 이용하여 구한 결과, 소결온도가 높아질수록 정전용량은 증가하였으며, 측정온도가 놓아질수록 높아지는 경향을 나타내었다. 입계의 정전용량은 소결온도가 높아질수록 높아 지지만 측정온도가 높아질수록 낮아지는 경향을 나타내었다. 각 저항값은 소결온도 및 측정온도가 높아질수록 지수적으로 감소하였다. 또한 분포함수를 이용하여 입계 안정성에 대하여 고찰하였다.

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Characteristics of Ultrafiltration and Spray Drying for Crude Protein Bound Polysaccharides Isolated from Agaricus blasei Murill (아가리쿠스버섯에서 분리한 조단백다당류의 막분리 및 분무건조 특성)

  • 홍주헌;윤광섭;최용희
    • Food Science and Preservation
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    • v.11 no.1
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    • pp.47-52
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    • 2004
  • This study was conducted to investigate the characteristics of ultrafiltration and spray drying process for crude protein bound polysaccharide(CPBP) isolated from Agaricus blasei Murill. In ultrafiltration process, the permeate flux increased with the increase of operating pressure and temperature. The permeate flux declined continuously while the fouling materials were accumulated on the membrane as the operation time increased. In comparing of raw CPBP and filtered CPBP, the viscosity of CPBP treated UF was decreased and $\Delta$E value of treated samples was increased. Thermal efficiencies of spray drying process were increased by increasing inlet temperature, feed rate and feed concentration.